Removable spark-plug.



W. FALWELL.

REMOVABLE SPARK PLUG.

,nrmunxon nun mac. 6, 1909.

1 Q Patented Deb. 13,1910.

1a all a... may 65mm.-

' UNITED TAI S Pe i -Em"QFF many rnnwnnnor sos'rou, massncnusnr'rs, 'ass mnon, Biz DIRECT m musm:

ASSIGNMENTS, '10 WRAY manumcrnmuc comm, A conromrron or massacnusnrrs. j

. movannn" sneak-rural Be itknown that I, WRAY citi-' zen ofthe UnitedStates, residing at Boston, 1n the'county of Suffolk and-Stateof Massachusetts', have inventedcertain new and use- .ful Improvements in Removable .Spark- Plugs, of which the following is a specifitcatlony v U My invention relates to removable sparkplugs for use in internal combustion en- .gines, and its objects are. to simplify the. parts thereof andrender the same more ac-.

cessible, to protect from injury the insulatlon between the electrodes, to prevent the leaking of the combustion gases and the 1 productlon ofshort circuits in the sparking circuit, to

ermitthe manual removal of both electroc es without removing the holder of the same. to provide a means of securely locking both electrodes to' the holder when in use, and to render more efl'ective the production and action of the igniting sparks.

It consists of a-spark plug, the central electrode stem of which is mcased in a thin metallic sleeve surrounded by insulating'materialfwhichmaterial .is inclosed in a protective metal case or shell formin the outer or grounded electrode and provi ed 'with a cap of wood fiber, hard. rubber or other suitable material.

It further consists in constructing a holder,v

having a thread at one endto screw into an orifice inthe combustion chamber, and havinga thread at the other end designed to engage with the interior thread of a hollow head, which head is adapted to secure and.

' holdthe two electrodes by means of lugs on i from the'n'earest contact .trode.

the exterior surface of the. outer electrode.

It further consists in constructing spark-' ing terminal points for the central electrode stem, said points being atvarying distances with the outer elec- 'It further consists in other improvements more specifically illustrated in the drawing and pointed out and claimed in the following specification.

' Figure 1; isa plan view of my improved spark plug and holder therefor. Fig.2. 1s

a side;el evation of the same. Fig. 3. is a view of-the lower extremlty of the central electrode showing the sparking terminal grounded electrode.

specmc aon m Patented Dec; 13, 1910.. l 'A pplidation filed December 6,1909. Serial No. 531,484.

44 of Fig. 1. Fig. 5. isa horizontalv section of Fig.-- 2. on line 5--5 looking in the direction of the arrow.

Similar numerals of designation refer to similar parts throu hout the several views.

Referring to the rawing, the central electrode stem 6,'composed of any metal or substance of suitable conductivity, is for the points. Fig. 4. is a vertical section on line greater portion thereof inclosed by the metallic sleeve 7 the lower part of saidstem normally projecting. from the base of said sleeve and forming a head 8, and the upper part normally projecting above the top of said sleeve, for'the purpose hereinafter described. I prefer to make the said stem 6 of but slightl smaller diameter than the sleeve 7, in or er that the two may fit. closely together, but at the same time to permit them to be'readily disassociated when it is desiredto take my invention apart. Around the said sleeve, completely inclosing the same, is a thick layer or coatm 9, of insulating material which is prefera ly porcelain, but may be of any substance suitable for the purpose, the said layer 9havin an outside shell or jacket 10 of metal whic 1 formsthe The-ends of the said shell" 10 extend slightly beyond each extremity of the sleeve 7 in order to permit the formation of the cup-shaped depressions 11 and 12in the ends of said insulating material, the extremities of the sleeve 7 ,bein said depressions.

(y so shaping said insulating material an inclosing it as aforesaid, I am able to protect the same com pletely against external or internal violence, there being no exposure in such construction to injury by, the use of wrenches, tools or the like, the outer and inner metallic shells aifording an armored covering for the inner and outer portion of the insulatin material at' the parts where breakage woul belikely at the lowest point of to occur and therebeing none of the said material projecting from its casings, or being exposed as is common in other sparkplugs now on'the market. In order to prevent any possibility of the said msulatlon escaping from its armored covering, 1- pro videannular recesses 13 into which protrude portions of the said insulation. As a further I 'th6 other in'- order that where a. magneto furnished produces a -much weaker spark than when running at a high rate of speed, and that at a low rate of'speed-the. spark is produced from'the nearest point only and Q f protection to the upper extremity of said insulation and as a means for conveniently handling the spark-plug when -heated, 1' prefer -to'-mount the cap let, formed of wood fiber or'oither material which. is both an insulator and a poor conductor-pf heat, upon the stem 6, bringing said cap into close contact with the upper portion of the shell 10 and thereby preventing oil, dirt, or the like from. littering the same. Upon the head 8 "atthe lower end of the electrode stem are mounted j'the terminal points 15- and 16,

which are-composed" of suitable material preferablv platinum or nickel and which may be of any number but arehereshown astwo in number, and are p'reterablj made integral ,with said head '8', and located entirelyewithin the depression 12. Preferably one of said terminal points is,-nearer the inner .edge of the grounded electrode than is used to generate thecurrent .the igniting sparks maybe used to greater advantage,

since I have found that when the magneto ismoving at a low rate of speed, the current is of much greater size and utility thanwheii it is dlVlClQdfllllOllg a plurality ot-polnts, all

at the same distance from the grounded elec- 'tlOdG. W hereas at a-high rate of speed, the

-. magneto furnishes a current of much. greater; strength wh ch produces a spark.

from 'all' the points. I am thus enabled to produce a more positive ignitionat all speeds. than that in common use. -.-In my ingenti'on it, is obvious that the terminals; are arranged-at such a distance from the groundfe'd; electrode that the current will only jump acrcfssi on the. nearerterniinal' on low speed, thetermina ls 'on higlrspeed, suc'h arrangement being. easily determined 45 and by actual experiment." In order-that" the 'posit1on of;sa1d terminals may be readily changed in relation to the outer elect-rode, I

prefer to construct them of metal sufficiently flexible to permit themto be bent into proper adjustment. Upon the upper end of the said stem arem'ounted the binding nut 26. and the' thumb screwQ? tor the purpose of afi'ording a binding post for electrical connection with tliewire from thegenerator: the circuit being completed through the steel framework of the motor car to the binding post on the circuit breaker as is well known in theart. I

All the above specific description applies particularly to the spark-plug as a'whole,

'w'hich is complete in itself and is designed to I vbe readily removed inits entirety from the" combustion chamber or installed therein in a verv short space of time without the use of, wrenches or tools. For the purpose of said attachment, I employ a holder 17, which is formed with a screw thread at the base.

thereof for the purpose of engaglng with the screw-threaded orifice in the combustion chamber (notshown') and to be firmly secured therein, suchengagement being effected-by means of a wrench applied to the .nut- 18 formed upon'the exterior of said holder and being integral. therewith. The interior of said holder is made hollow for :the purpose of permitting the insertion of the spark-plug above described, so that the ends of the electrodes shall be in proper position in the combustion chamber.- To this end, the said spark-plug is constructed with aneulargement about-the central por-' tion thereof and formingan abutment 19 which engages with a shoulder in said holder, the interior thereof being shaped to permit a close contact of all the parts of both plug and holder exceot at the top of the holder where an annu arjrecess 20 is formed. :Into said annular recess projectthe lugs 21' formed upon theexterior of the sparkplug. and over the top of the holder is secured thehollow head .22, the upper'end of said'holder being threaded to engagewith the th'read on the interior of said head.--

The releasing or tightening of said head is effected bvmeans of the handle 23, which is made integral therewith. (See Figs. Qand.)

To permit the ready introduction and re- IlOYal of the spark-plug, the top of the head 22 is provided with the openings 2% which permit-egress or ingress of the lugs 21 and the-"consequent removal of the said plug.

The stop 25 lo'cated on the under side of the top of the head and integral therewith (see Fig. .5) permits one of the lugs to 15s turned against the same and the head ma; then be screwed downby means of the handle 23 and firmly secured. I preter tolocate the stop flush with one-side of one of the openings 24-. in order that one (if the lugs-may be turned so as to engage the same and be brought directly beneath said open-- ing 24: when thesaid head 22 is loosened.

. F orthe purpose of protecting the open- .its ready introduction and removal, and serving the purpose of a sparking area or.

sparking points. 0

The manner or attaching my improved spark-plug is as follows :v In the first instance.

the holder 17, is-screwed into the orifice proin thecombustion chamber and is mly andfper nanently secured therein.

The spark-plug is then placed in the holder and the lugs inserted through the openings T -li' 25L, Upon turning-the plug until one of the lugs abuts against the stop 25, and screwing r l have fo'und from experience that-the en'- p osed position of'su'ch porcelain renders it extremely liable'to injury not only from the use offr'emoval tools but from. changes of 1 temperature and other causes. The impor-- tancei of protecting the interior surface of thejinsulation appears to havel' been com- I pletel'y overlooked in prior devices, the possibilityg-" of injury from inserting or' withdrawing the electrode stem not being consided, I also believe myself to'bethe first to 1 'construct a spark-plug which can becom- I pletely removed from the combustion cham -tflber or installed therein without the use of- '-twr enches andtools. Iam aware that there I are in part/removable :without the meet ."tool s,- the inner electrodebein detachable J -f-"flforn,;the outer electrode which is left in the orifice-of the combustion chamber, but I- am ""notiaware of any'mea-ns for-manually rcif trodes; This disassoci'atlon of parts of the --jplug's.:u sed in the prior art as above" set forth moYi g'the-- entire plug including both elect is'open-"to'grave objection. It has been my jsexperienc'e; that where. one electrode is removed and another inserted in its place, it is 15; "almost certain that theterminals ofthe two i electrodes are 'not. in proper relationship,

- Qand the onlycertain means of insuringade quate adjustment is by removing the grounded electrode as well as the'inner electrode, a proceeding involving much time and. difliealty. To insure good results from the fpractical' standpoint, I have found that it 1s essential to' preserve a constant relationshi between the terminals of the electrodes anc that anything occasioning the disturbance of suchrelationship is practically certain to del which they are used. v v

One. great diflicult heretofore experienced fywith spark-plugs of,the prior art is from thecondensing of the combustion gases upon the insulation and parts of the plug adjacentto the electrodes, and the production of .are-sparkeplngs now on the market which st'roy the efficiency of the spark-plug inshort circuits occasioned thereby.v This is primarily due because of openin s or'crevices betw'een the electrodes which permit gases and other'ma'tter to accumulate theren and to condense upon the electrodes and in numerous instances to cause said gases to leak out through the pin Particularly is. this defect observable w ere plug are designed to be ma e removable after the plug isinstalled, as for instancewhere theelectrodes are disassociated, one being left in thecombustion cha'mber. Such defect is entirely overcome by the construcarts of the tion and arrangement of the parts of my spark-plug, there being no openings in which said gases can collect or through which they can pass to the outside air, all said parts being hermetically closed. v

What I claim and desire to secure by Letters Patentis 1. In a s ark-plug: a metallic shell electrode, a hol ow metallic holder shaped to re-' ceive and hold said electrode, and having an annular recess therein, 111 located upon said electrode and forme to be inserted within said recess, combined with a head for securing said electrode therein, and means for withdrawing sa1d electrode from said holder without removing said 'head therefrom.

2. In a spark-plug: a metallic shell electrode, a hollow metallic holder adapted to receive and hold said electrode and having an annular recess therein, lugs located upon said electrode and formed to be inserted.

within said recess, combined with a head threaded to engage with the top of said holder and to be turned down upon the same, and to secure said elect-rode, saidhead having openings through which said shell electrode may be inserted or withdrawn when said head is loosened. I

3. In a spark-plug: a metallic shell electrode, a hollow metallic holder adapted to receive 'andhold said electrode and having an annular recess therein, lugs located upon said electrode and formed to. be inserted within said recess, combined with a head threaded to engage with the top of said' holder and. be turned down upon the same,

and to secure said electrode, said head having openings'through which said shell electrode may be inserted ori'withdrawn when said head is loosened, and a handle secured to said head for the purpose of turning the same. a v

"'4. In a spark-plug: a metallic ,shell electrode, a hollow metallic holder adapted to receive and hold said electrode and having an annular recess therein, lugs located upon said electrode and formed to be inserted within said recess, combined with a head threaded to engage with the top' of said holder and be turned down upon the same,

aild to secure said elctrddq,x.ai dz'head 11w, 'i'ng openings through which; saidghell ele'e' Ptrode may. be insertec'lj(if wifihdrawgn' Whnsaid head 'is loosened, 'andii 'said he ad being providedwvith- 'astop-sitpified abth side of one of thefopen-ings threughrwhichthehlgs a e Withdrawf 

